1. Field of the Invention
The present invention provides a method for anterior cruciate ligament reconstruction and, more particularly, a method for single tunnel double bundle anterior cruciate ligament reconstruction.
2. Related Art
Single tunnel single bundle anterior cruciate ligament reconstruction (STSBACLR) has long been established as a method of anterior cruciate ligament (ACL) reconstruction. A variety of graft choices are available to surgeons during ACL reconstruction. These choices include autogenous patellar or quadriceps tendon with bone blocks, or hamstring tendons. In addition, changed here tendon allografts (from donors) may be used. The main portion of the ACL which needs to be reconstructed is the anterolateral bundles. Arthroscopic assisted or open ACL reconstructions involve removing the remaining native ACL and drilling a tunnel at the anatomic attachment site of the anterolateral or posterior medial bundle at the anterolateral wall of the intercondylar notch. This tunnel is drilled in line with the roof of the notch and about 1-3 mm from the posterior articular surface of the lateral femoral condyle. The tibial attachment site is then prepared by identifying the normal attachment site of the ACL at the bottom of the ACL facet. A tibial tunnel is drilled, at approximately a 60 coronal° angle and about 3-6 cm from the joint line, from anterior to posterior. Once the tunnels are drilled, sharp edges and soft tissues around the tunnel exit site are smoothed off with the use of a rasp. The graft is then passed into the joint and fixed in its femoral tunnel (usually with an interference screw). The graft is then tensioned distally while the knee is cycled several times to remove any slack in the graft. The graft is fixed to the tibia, usually with staples, while the knee is flexed 15-30°, distal traction is placed on the graft, and a posterior force is applied to the tibia. After fixation, the anterior cruciate drawer is assessed to verify a return of normal anterior stability to the knee, and the surgical incisions are closed.
Double bundle double tunnel anterior cruciate ligament reconstruction (DBDTACLR) has recently been described as a technique for ACL reconstruction which provides two bundles of tissue in separate tunnels. Recent biomechanical studies have shown that an anatomic double-bundle ACL reconstruction is superior in restoring normal knee laxity compared with the conventional single-bundle isometric reconstruction. One technique uses a double-bundle Y-shaped hamstring tendon graft. A double- or triple-bundle semitendinosus-gracilis tendon graft is utilized and directly fixed with interference screws. In the lateral femoral condyle, two femoral tunnels are created inside-out through a low anterolateral arthroscopic portal. First, in full extension, the double-stranded gracilis graft is fixed with an interference screw inside the lower femoral socket, representing the insertion site of the posterolateral bundle. In 90 degrees of flexion the combined semitendinosus-gracilis graft is pretensioned and fixed inside the upper femoral socket. Alternatively the graft is placed into the a single femoral tunnel and an interference screw simply placed between the grafts without respect for control of rotation and position of the graft to simulate true orientation of the grafts into anteromedial and posteriolateral bundles. The tendon is inserted in the tibial tunnel. Finally, pretension is applied to the bundles in extension and another screw is inserted. Alternatively two separate tibial tunnels are utilized and the separate anteromedial and posterolateral tunnels and fixed with staples or screws. Using this technique, the stronger semitendinosus part of the double-bundle graft, which mimics the anterolateral bundle of the ACL, is fixed in full extension, whereas the smaller gracilis tendon part (posteromedial bundle) is fixed in flexion.
Kinematically the double bundle anterior cruciate ligament reconstruction has shown itself to be more closely related to the actual normal motion of the knee when compared to single bundle anterior cruciate ligament reconstructions. DBDTACLR is technically demanding procedure requiring an extremely high level of surgeon skill. In addition DBDTACLR requires four separate fixation devices to secure the soft tissue bundles in place to recreate a torn anterior cruciate ligament. Each bundle of tissue is separately tensioned in the respective tunnel prior to fixation with orthopedic devices.